Next time a stranger comments on your breasts in public, just shoot him—with a camera, such as the one built into your cell phone.

This is the unorthodox advice of Holla Back NYC, a blog-cum-grass-roots movement that uses digital technology to combat street harassment. They urge women not only to take a photo when men hassle or insult them in public, but to make the photo public on www.hollabacknyc.com.

Women and men from New York City and elsewhere have posted snapshots (sometimes blurry) and stories (often grisly) to the website; the worst of which end up in the “Holla Shame.” Although participants have been called vigilantes by some, they insist their aim is not to catch or punish the men who catcall on the street. Rather, they want to provide women with an alternative to the helpless feeling of being sexually objectified by a stranger.

“When I didn’t do anything [to respond], it didn’t feel good, and when I yelled back it didn’t feel good, but now I have a response that genuinely feels good,” says Emily May, 25, one of the seven friends who founded the group. “I don’t feel victimized anymore.”

Hollabacknyc.com was created last summer by four women and three men in their 20s who were fed up with the way harassers are ignored and tolerated. The website receives an average of 1,500 hits per day and has inspired Holla Back sites for Boston, Washington, D.C., and the European Union. “We believe we’re on the cusp of street harassment being the next big feminist issue, like workplace harassment,” says May.

To raise public awareness about harassment, the group organizes events with other activists and nonprofits. For example, they plan to join with the Blank Noise Project in India to host an event to counter the stereotype that men only hassle women in skimpy clothing: They’ll exhibit actual clothes women were wearing when harassed.

Such grassroots action is vital, because street harassment is a very difficult crime to deal with by law, says Marty Langelan, author of Back Off: How to Confront and Stop Sexual Harassment and Harassers (Simon& Schuster, 1993—see Ms., Fall 2005, for Langelan’s practical anti-harassment guide). “Most cities do not even have ordinances that would make it a misdemeanor, and even in cities that do, such as Washington [D.C.] ... police won’t make an arrest unless they witness the behavior and consider it threatening. But [police] are [most often] males with guns, and not much is threatening to them.”

Women, on the other hand, may feel threatened even by statements that seem to be compliments—because they may be the precursor to more lewd or injurious conduct. (Indeed, Langelan urges women to be cautious about photographing harassers who seem at all violent.)

“Most of the guys I’ve spoken with can’t believe that the problem is really that big a deal,” adds Katie Runyan, 23, who founded Holla Back D.C., a group with whom Langelan plans to work. “They seem to believe that it’s a mild annoyance or that it only happens once in a while. This proves to me exactly why this site needs to be created.